Radio telecommunications networks include large numbers of components, which must be connected together. As examples, a network will typically include radio base stations (RBS) and base station controllers (BSC), which are connected together through routers and digital cross-connect (DXC) equipment. These components are generally referred to herein as network elements (NE).
Connections between network elements are typically E1/T1 connections, and are divided into frames, each frame including a plurality of time slots. E1/T1 frames consist of 32 or 24 time slots, respectively. If a connection uses all 32/24 time slots, this is referred to as a whole E1/T1 connection.
However, in many cases, the connection between two network elements is some fraction of an E1/T1 connection. This situation arises in particular when two network elements are connected through a digital cross-connect device, since this can multiplex links to two different network elements onto a single link to a third network element.
It is also necessary to consider whether the equipment supports time slot integrity. If so, each time slot has the same delay when passing through the equipment. However, some devices do not support time slot integrity, that is different time slots have different delays. In that case, for many applications, the differences must be compensated for. One example is if communication with the Internet Protocol (IP) protocol suite is used.
When establishing a connection between two network elements, for example when adding a new network element, it is advantageous to allocate the largest available number of time slots. Also, it would be advantageous for the set up procedure to be automated, in order to reduce the requirement for operator intervention during the set up procedure.
WO99/56485 describes a system in which a base station controller controls and monitors the installation of network elements, and automatically allocates telecommunications capacity for the use of the network elements. The required capacity is allocated from a group of unallocated consecutive time slots on a communications link, one of those time slots being used as a communication channel, for the base station controller to send time slot allocation information to the network element.
However, the need to use one of the time slots as a communication channel in this way reduces the bandwidth available for transmitting data between the network elements.
Moreover, in order for the base station controller to be able to allocate the available capacity, it must have information about the time slot connections of the cross connects.